Portable X-ray device

ABSTRACT

A portable and preferably hand-held X-ray generator for use in intraoral and other X-ray applications, and a new process of dental image acquisition which utilizes a novel receptor holder physically linked to the lightweight, portable generator, and a unique, articulating arm and cradle which allows one generator to be used in multiple operatories. The system&#39;s generator has a reduced X-ray output and much smaller focal spot area than conventional dental X-ray generators, which reduces the X-ray output and the overall patient X-ray burden. The smaller focal spot also allows for improved resolution in the final image.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is related to provisional patent applicationSer. No. 60/004,988, filed Oct. 10, 1995 by Melvin P. Sledband andentitled HAND X-RAY UNIT WITH SMALL GENERATOR, TUBE AND TUBEHEAD, whichapplication is incorporated by reference herein in its entirety.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is related to provisional patent applicationSer. No. 60/004,988, filed Oct. 10, 1995 by Melvin P. Sledband andentitled HAND X-RAY UNIT WITH SMALL GENERATOR, TUBE AND TUBEHEAD, whichapplication is incorporated by reference herein in its entirety.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to X-ray devices and, moreparticularly, to portable X-ray devices.

BACKGROUND OF THE INVENTION

For decades, medical professionals, such as dentists, have routinelyused X-ray radiographs for disease detection, diagnostic decision makingand treatment monitoring. X-rays are emitted by an X-ray generator, passthrough the structures of interest such as teeth, bone and soft tissuesof the head and jaws, and are captured by an appropriate receptor. Thetraditional receptor, X-ray photographic film, is still the most widelyused. In such film-based systems, the latent image is produced on thefilm through activation of silver halide crystals which are thenrendered visible by processing the exposed film in chemical solutions.Such film processing takes several minutes when a series of X-ray filmsare exposed on the patient. If, after developing, the images arediscovered to be unusable due to film placement or image geometryerrors, a new series of films need to be exposed. This increases thepatient x-ray dose.

Recently, systems have been introduced for electronic acquisition ofdental X-ray information through the use of charge coupled device (CCD)image receptors. Current CCD receptors for oral, intraoral andmaxillofacial imaging tasks use either radiation-hardened CCD arrays(Regain SensAray, Sundvaal, Sweden) or CCD arrays coupled to ascintillator such as a rare-earth X-ray screen material (TrophyRadiologie, Vincennes, France). The largest area array currently used indental imaging is now approximately 760 pixels by 524 pixels (SchickTechnologies, New York), which results in a resolution of about 10 linepairs/mm.

Imaging with a CCD receptor requires approximately 70-80% less exposuretime than imaging with X-ray film. Thus, the patient X-ray dose islessened. However, most current X-ray generators were designed for usewith film receptors; consequently, they produce too much X-rayradiation, overloading the CCD receptor and increasing the patientabsorbed X-ray dose.

Another problem with current X-ray generators is that they are large andheavy, thereby requiring that they be installed in a fixed location. Fordental applications, the X-ray generator is typically fixedly mounted tothe distal end of an articulating arm which is in turn mounted to thewall of the dental operatory. The weight of the tubehead often requiresthe placement of additional support in the wall where the unit ismounted in order to support the tubehead at its maximum length from thewall Because a dental office normally includes several operatories, theprovision of X-ray imaging capability to each of the operatoriesrequires a substantial investment since multiple X-ray units must bepurchased.

There is, therefore, a need for an X-ray device that will lessen thepatient X-ray dose. There is also a need for an X-ray device that caneasily be used in several different operatories in order to reduceduplication of equipment within the dental office. The present inventionis directed toward meeting these needs.

SUMMARY OF THE INVENTION

The present invention relates to a portable and preferably hand-heldX-ray generator for use in intraoral and other X-ray applications, and anew process of dental image acquisition which utilizes a novel receptorholder physically linked to the lightweight, portable generator, and aunique, articulating arm and cradle which allows one generator to beused in multiple operatories. The system's generator has a reduced X-rayoutput and much smaller focal spot area than conventional dental X-raygenerators, which reduces the X-ray output and the overall patient X-rayburden. The smaller focal spot also allows for improved resolution inthe final image.

In one form of the invention, a portable X-ray device is disclosed,comprising a handle configured to be held by a single hand; an X-raytube mounted within the handle; a collimated tube mounted to the handleand positioned such that X-rays will be emitted into the collimated tubewhen the X-ray tube is activated; wiring extending between an interiorof the handle and an exterior of the handle and operative to couple anexternal power supply to the X-ray tube; an enable switch mounted to thehandle; and an exposure switch mounted to the handle; wherein the X-raytube will only emit X-rays when the enable switch and the exposureswitch are both depressed.

In another form of the invention, a portable X-ray device is disclosed,comprising an enclosure; an X-ray tube mounted within the enclosure; acollimated tube mounted to the handle and positioned such that X-rayswill be emitted into the collimated tube when the X-ray tube isactivated; wiring extending between an interior of the enclosure and anexterior of the enclosure and operative to couple an external powersupply to the X-ray tube; and power supply circuitry operative togenerate a voltage to drive the X-ray tube, wherein the power supplycircuitry is not contained within the enclosure and is coupled to theenclosure by the wiring; whereby a weight of the enclosure issignificantly reduced.

In another form of the invention, an X-ray image receptor holder adaptedto be coupled to a source of X-rays is disclosed, the holder comprisingan image receptor holder coupled to the collimated tube, the holdercomprising: a horizontal member having proximal and distal ends; avertical member attached to the horizontal member distal end andextending transversely thereto; and a transverse sliding member mountedto the horizontal member and operative to slide thereon in alongitudinal direction; wherein an X-ray image receptor may be heldbetween the vertical member and the sliding member.

In another form of the invention, a method for generating an X-ray imageis disclosed, comprising the steps of: (a) providing a portable X-raydevice, comprising: a handle configured to be held by a single hand; anX-ray tube mounted within the handle; a collimated tube mounted to thehandle and positioned such that X-rays will be emitted into thecollimated tube when the X-ray tube is activated; wiring extendingbetween an interior of the handle and an exterior of the handle andoperative to couple an external power supply to the X-ray tube; anenable switch mounted to the handle; and an exposure switch mounted tothe handle; wherein the X-ray tube will only emit X-rays when the enableswitch and the exposure switch are both depressed; (b) grasping thehandle with a single hand; (c) depressing the enable switch with a firstfinger of the hand; (d) aiming the collimated tube at an X-ray imagereceptor, wherein a structure to be imaged is positioned between thecollimated tube and the receptor; and (e) depressing the exposure switchwith a second finger of the hand while holding the enable switch in adepressed position.

In another form of the inventor a method for generating an X-ray imageis disclosed, comprising the step of: (a) providing a portable X-raydevice, comprising: an enclosure; an X-ray tube mounted within theenclosure; a collimated tube mounted to the handle and positioned suchthat X-rays will be emitted into the collimated tube when the X-ray tubeis activated; wiring extending between an interior of the enclosure andan exterior of the enclosure and operative to couple an external powersupply to the X-ray tube; and power supply circuitry operative togenerate a voltage to drive the X-ray tube, wherein the power supplycircuitry is not contained within the enclosure and is coupled to theenclosure by the wiring; whereby a weight of the enclosure issignificantly reduced; (b) providing an articulating arm having a cradlethereon, wherein the cradle is adapted to hold the X-ray device whenplaced therein; (c) aiming the collimated tube at an X-ray imagereceptor, wherein a structure to be imaged is positioned between thecollimated tube and the receptor; (d) moving the articulated arm suchthat the cradle will hold the X-ray device; (e) depressing an enableswitch; and (f) depressing an exposure switch, wherein the X-ray devicewill not emit X-rays unless both the enable switch and the exposureswitch are depressed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side cross-sectional view of a first embodimentportable X-ray generator of the present invention.

FIG. 2 is a schematic circuit diagram of a power supply circuit of thepresent invention.

FIG. 3 is a schematic circuit diagram of a timing and control circuit ofthe present invention.

FIG. 4 is a schematic circuit diagram of an X-ray generator drivingcircuitry of the present invention.

FIG. 5 is a side elevational view of a first embodiment receptor holderof the present invention.

FIG. 6 is a first end elevational view of the receptor holder of FIG. 5.

FIG. 7 is a second end elevational view of the receptor holder of FIG.5.

FIG. 8 is a side elevational view of a second embodiment receptor holderof the present invention.

FIG. 9 is a cross-sectional view of the receptor holder of FIG. 8.

FIG. 10 is a side elevational view of the portable X-ray generator ofthe present invention making an X-ray image of a maxillary tooth.

FIG. 11 is a side elevational view of the portable X-ray generator ofthe present invention making an X-ray image of a mandibular tooth.

FIG. 12 is a perspective view of a dental operatory including theportable X-ray device of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiment illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended, such alterations and furthermodifications in the illustrated device, and such further applicationsof the principles of the invention as illustrated therein beingcontemplated as would normally occur to one skilled in the art to whichthe invention relates.

The present invention relates to a portable and preferably hand-heldX-ray generator for use in intraoral and other X-ray applications, and anew process of dental image acquisition which utilizes a novel receptorholder physically linked to the lightweight, portable generator, and aunique, articulating arm and cradle which allows one generator to beused in multiple operatories. The system's generator has a reduced X-rayoutput and much smaller focal spot area than conventional dental X-raygenerators, which reduces the X-ray output and the overall patient X-rayburden. The smaller focal spot also allows for improved resolution inthe final image.

Referring to FIG. 1, a preferred embodiment of the portable X-raygenerator of the present invention is illustrated and indicatedgenerally at 10. The X-ray generator 10 is illustrated incross-sectional view in FIG. 1 and includes a "pistol grip" handle 12 towhich is attached a rectangular collimated tube 14. The handle 12 andtube 14 are preferably formed from LITHARCH lead ceramic material orfrom a lead-lined, high density plastic. The distal opening 16 of thecollimated tube 14 is preferably 2.5 centimeters by 3.0 centimeters. Thesize of the distal opening 16 is preferably sized to be just slightlylarger than the receptor size to be used with the X-ray generator 10.The proximal end of the tube 14 includes a rectangular, aluminumcollimator which has an aperture (port or exit) of approximately 3millimeters by 5 millimeters.

An X-ray receptor 20 is provided for recording the X-ray image. TheX-ray receptor 20 may be any device which is sensitive to X-rayradiation, such as X-ray film or a CCD sensor. The receptor 20 isillustrated as a CCD sensor in FIG. 1, including the wiring 22 which isused to couple the CCD receptor 20 to a recording and display device asis known in the art. The CCD receptor 20 is positioned in a receptorholder 24 which is coupled to a rod 26 which is adapted to fit withinany one of a plurality of docking slots 28 formed on the distal end ofthe collimated tube 14. The design and operation of the receptor holder24 and docking slots 28 is discussed in greater detail hereinbelow.

The handle 12 of the X-ray generator 10 includes an X-ray tube 30 andassociated driving circuitry 32. The X-ray tube 30 and driving circuitry32 are described in greater detail hereinbelow with respect to FIG. 4.Because it is desired that the present invention comprise a portable andpreferably hand-held X-ray generator, the isolation transformer normallyused in X-ray generators has been eliminated in the present invention.Furthermore, the high voltage transformer is not placed within thehandle 12, but is remote from the X-ray generator 10 and the highvoltage signal is wired from the high voltage transformer to thecircuitry 32 within the handle 12, as explained in greater detailhereinbelow. The handle 12 is filled with oil or preferably gas in orderto dissipate heat generated by the X-ray tube 30, as is known in theart. The distance from the collimator 18 to the distal end 16 of thecollimated tube 14 is preferably 15 centimeters.

The rectangular, collimated tube 14 is much smaller than theconventional round cone used in almost every prior art dental X-raytubehead. The diameter of the prior art round cone is approximately2.75", whereas the tube 14 dimensions are preferably only 2.0"×1.5".This smaller size is possible because the receptor is uniquely fixed tothe generator. This arrangement leads to smaller skin surface X-ray doseand to a potential X-ray dose reduction by eliminating retakes of filingbecause of verticaI or horizontal angulation errors which occurfrequently when a free-floating conventional tubehead is aimed at thefilm by the operator. In addition the preferred 0.3 mm focal spot is 1/2the size of the smallest focal spot presently available in the prior artdevices.

The various input and output connections of the circuitry 32 are coupledto an electrical connector 34 mounted in the base of the handle 12.These connections are described in greater detail hereinbelow. Alsocoupled to the connector 34 are an enable switch 36 and a fire switch38. The enable switch 36 is preferably located on the handle 12 at aposition where it will be convenient to be depressed by the index fingerof the user. As described in greater detail hereinbelow, the enableswitch 36 initiates current flow to warm up the X-ray tube 30 prior toactual firing of the X-ray generator 10. After the enable switch 36 hasbeen depressed, the operator depresses the fire switch 38 in order toactivate the X-ray generator 10. The fire switch 38 is preferablylocated on the handle 12 at a position which is conveniently accessed bythe operator's thumb. The two switch configuration should act as asafeguard against inadvertant firing of the unit and is described ingreater detail hereinbelow. Those skilled in the art will appreciatethat the wiring within the handle 12 may be hard-wired to the externalcircuitry rather than using the electrical connector 34.

Referring now to FIG. 2, a power supply circuit for the hand-held X-raygenerator of the present invention is illustrated, and indicatedgenerally at 40. The power supply circuit 40 is preferably not containedwithin the handle 12 in order to reduce the weight thereof. Instead thepower supply circuit 40 is contained in a separate housing and iscoupled to the handle 12 via cabling (see FIG. 10). The circuit 40 iscoupled to a standard 110 volt power line at inputs 42 and 44. The 110volt inputs 42 and 44 are coupled to a 12 volt regulator 46 in order toproduce the 12 volt output 48, as is known in the art. The power lineinputs 42 and 44 are further coupled to a full wave rectifier D1. Theoutput ports of the full wave rectifier D1 are placed across the 1,000uF capacitor C1. The voltage placed across the capacitor C1 is typically160 volts DC. A switching regulator controller chip U5 (such as aSG3524) produces two control outputs CA and CB which are coupled to thetransformer T1. The transformer T1 preferably has a 120 turn centertapped primary and an 84 turn center tapped secondary. The transformerT1 combines the two control signals into a single signal feeding aseries power field effect transistor (FET) Q7.

The duty cycle of the power FET Q7 determines the output voltagepresented at output ports 50 and 52. The switching regulator U5 feedscurrent to a series inductor L1 and that current (i) increases at a ratedetermined by the voltage difference (v) across the inductor L1 and theinductance (L) according to the formula:

    v=Ldi/dt.

After a few microseconds, the FET Q7 is switched off and the inductanceL causes the input voltage of the inductor L1 to switch rapidly toground, where it is caught by the clamp diode D5, at which point thecurrent starts to ramp down according to the following formula:

    v'=-Ldi/dt

(where v' is the output voltage appearing across the terminals 50 and52).

The ratio of the on and off times determines the output voltage and theswitching regulator U5 controls this. The switching regulator is veryefficient, and generates very little heat and the parts for the powersupply circuit 40 are small and inexpensive. It will be appreciated bythose skilled in the art that the circuit 40 is essentially tied to thepower line at the inputs 42 and 44, with only the rectifier D1 forisolation. The present invention, therefore, eliminates the isolationtransformer normally used in such systems in order to keep the systemsmall and light weight. The output voltage appearing across theterminals 50 and 52 is nominally +100 VDC, but may be set anywherebetween +40 and +120 VDC in order to set the X-ray tube 30 anode voltagebetween 20 and 80 kVp.

Referring now to FIG. 3, a control circuit of the present invention isillustrated and indicated generally at 60. The control circuit 60 ispreferably mounted in the same housing as the power supply circuit 40(see FIG. 10). The control circuit 60 uses a dual monostablemultivibrator UIA and UIB (preferably a 4538) in order to generate twotiming signals: the filament pre-heat signal and the exposure timesignal. A short negative pulse to pin 11 of UIB causes pin 9 of U1B toswitch from +12 V to ground for 1.0 second and then return to +12 V. Theoutput signal on pin 9 of UIB is coupled through the diode D2 to theadjustable switching regulator U3 (preferably a LM1575adj, manufacturedby National Semiconductor), as an enable signal. The switching regulatorU3 produces an output voltage which is applied to output port 62 and isadjustable from +2 V to +11 V. The output port 62 is coupled to thecenter cap of the filament transformer T10 of FIG. 4.

The circuit of U4, Q3 and Q4 comprise a square wave power generatorwhich is coupled to the filament transformer T10 of FIG. 4 via theoutput ports 64 and 66. Adjustment of the variable resistor R12 (coupledto U3) will set the filament voltage, and thus the X-ray generator tube30 anode current. This filament current is on whenever U3 is enabled.

When the 1.0 second time interval ends, pin 10 of U1B feeds a signal topin 5 of U1A in order to generate the exposure gate at pin 7 of U1A. Theexposure gate signal feeds another diode D1 in order to enable U3 sothat the filament circuit is energized for the sum of the pre-heat time(1.0 second) and the exposure time, whatever the exposure time may be.The exposure time is determined by the product of R1 and C1 at the inputof U1A. A 0.1 second exposure time is indicated by the values of FIG. 3.However, R1 and C1 may be changed by a simple switching circuit so thatvariable exposure times can be selected by the operator. The resistanceand capacitance values made available to the operator by such aswitching circuit would be determined by the desired application for theX-ray generator. In a preferred embodiment, exposure times of 0.04,0.06, 0.08, 0.10, 0.15, 0.20, 0.30, 0.40, 0.50 and 0.60 seconds areprovided.

The exposure gate signal at pin 7 of U1A is also sent as an enablesignal to U2 (preferably a SG3525), which is used as a low impedancesquare wave generator feeding two power FET's, Q1 and Q2. These twopower FET's feed the high voltage transformer T11. The output of thehigh voltage transformer T11 is coupled to the output ports 68 and 70,which feed the voltage multiplier in the X-ray generator handle 12 (seeFIGS. 1 and 4).

The circuit coupled to the ports 68 and 70 has a relatively largedistributed capacitance which is coupled through the secondary of T11 tothe primary of T11 as a relatively large capacitance. When the circuitswitches from Q1 to Q2 or back to Q1, this capacitance makes the primarycircuit of T11 look like a short circuit until that capacitance has beencharged. A current limiting circuit of some type must therefore be usedin order for the circuit to operate properly. In the present invention,the inductor L2 is used as a limiting inductor. When the capacitance isfully charged, the sudden change of current is limited by the inductorL2 and energy which is stored is released via the diode D4 into a smallload resistor R18. If the X-ray generator tube 30 should happen to arc,higher voltage transients are limited by the diode D5 to the raw +160VDC signal, which is sufficient to let transient signals dissipate theirenergy without damaging the FET's Q1 and Q2. Those skilled in the artwill recognize that the circuit 60 relies on the insulation oftransformer T11 and the insulation of filament transformer T10 (see FIG.4) in order to prevent any connection between the user and the powerline voltage.

A relaxation oscillator U20 (preferably a LM555) is also connected tothe exposure gate signal provided by pin 7 of UIA. At the start of thegate, U20 will activate its output at pin 3 and energize a small beeperand an LED in order to indicate the exposure. The on time of U20 isapproximately 0.5 seconds, enough to be seen and heard even when theactual exposure time is less than 0.01 seconds.

Federal safety rules and common sense require a "dead-man" switch to beincorporated into the control circuitry for an X-ray generator. Thismeans that the operator's exposure switch 38 will not permit X-rayemission from the X-ray generator tube 30 unless the dead-man enableswitch 36 is also currently depressed. This is accomplished with acommon relay 72 having contacts wired in series with the +100 VDC line.The enable switch 34 couples the +100 VDC voltage to the inductor L2 viathe port 74.

Referring now to FIG. 4, the circuitry 32 located within the handle 12of the portable X-ray generator is illustrated in greater detail. Thehigh voltage circuit 32 operates at 25 kHz and incorporates a voltage10-tupler. The filament circuit also operates at 25 kHz and thetransformer T10 secondary comprises just three turns of insulated wire.The size and weight of the high voltage circuitry 32 are relatively lowin order to allow the portable X-ray generator 10 of FIG. I to be easilyhandled by the operator. The filament transformer T10 utilizes a smallferrite core in order to further reduce the system weight.

Referring now to FIGS. 5-7, a first embodiment of the X-ray receptorholder 24 is illustrated. The holder 24 comprises a horizontal portion80 and an attached vertical portion 82. The X-ray receptor 20 fitssecurely within a recess formed at the junction between the members 80and 82 as illustrated. A slot 84 is formed in the vertical member 82 inorder to accommodate the wiring 22 which is used to control the X-rayreceptor 20 and to download information therefrom when the receptor 20is a CCD device. The horizontal member 80 includes a longitudinal slot86 therein in order to mount the positioning bar 26 which engages thedocking slots 28 of the X-ray tube 14. The use of the receptor holder 24mounted to the positioning bar 26 will automatically create perfectparallelism between the sensor 20 and the portable X-ray generator 10,thus eliminating beam alignment problems due to erroneous vertical andhorizontal angulations. In other words, the sensor 20 will always beperpendicular to the X-ray beam. This will reduce the patient's absorbedX-ray burden due to angulation errors, by eliminating retakes of poorlyaligned receptors 20. Furthermore, the holder 24 and beam alignment arm26 are detachable from the portable X-ray generator 10 and therefore maybe autoclaved for later reuse.

A second embodiment receptor holder is illustrated in FIGS. 8-9, andindicated generally at 24a. The holder 24a comprises a horizontalportion 80a and an attached vertical portion 82a. The horizontal member80a includes a longitudinal slot (not shown) therein in order to mountthe positioning bar 26 which engages the docking slots 28 of the X-raytube 14. The X-ray receptor 20 may be placed at the junction between themembers 80a and 82a as illustrated.

A slot (not shown) is formed in the vertical member 82a in order toaccommodate the wiring 22 which is used to control the X-ray receptor 20and to download information therefrom when the receptor 20 is a CCDdevice. The receptor 20 is held in place by means of a sliding box 88which rides within the track 90 formed on either side of the horizontalmember 80a. The sliding bar 88 allows the receptor holder 24 to be usedwith X-ray receptors 20 having any thickness. Because CCD receptors varyin thickness, and all are much thicker than X-ray film, the receptorholder 24a will accommodate any size receptor.

Referring now to FIG. 10, use of the portable X-ray generator 10 in adental application is illustrated, specifically with making an X-rayradiograph of a maxillary tooth 90. In this arrangement, the beamalignment arm 26 is placed in the lower docking slot 28 of the X-raytube 14. This allows the receptor 20 and receptor holder 24 to bepositioned within the patient's mouth and extend upwards behind themaxillary tooth 90. The corresponding positioning is shown in FIG. 11for use of the portable X-ray device 10 with a mandibular tooth 92. Inthis orientation, the beam alignment arm is inserted into the upperdocking slot 28 of the X-ray tube 14 so that the X-ray receptor 20extends in a downward direction behind the mandibular tooth 92.

One of the advantages of the hand held X-ray device 10 of the presentinvention is that the hand held nature of the device allows not onlyease of use by the X-ray technician, but also portability of the devicefrom operatory to operatory. Such portability allows for a singlehand-held X-ray unit 10 to be used in several different operatories,thereby greatly reducing the equipment and maintenance costs to theowner, such as a dentist, doctor, hospital, veterinarian, etc. Referringto FIG. 12, there is illustrated a first embodiment dental operatorywhich includes a portable X-ray device 10 of the present invention. Adental patient chair 100 is shown positioned next to a dental unit 102,which includes all of the tools and equipment needed by the dentistduring a dental session. An articulating arm 104 is coupled to thedental unit 102 by means of a suitable connection 106. Alternatively,the articulating arm 104 may be freestanding and incorporate its ownbase (not shown). The distal end of the articulating arm 104 includes acradle 108 which is adapted to releasably hold the portable X-ray unit10. The power supply and control circuits 40, 60 of the X-ray unit arehoused in an appropriate box which may be placed on or within the dentalunit 102. A cable 110 couples the portable X-ray unit 10 to thesecircuits. The articulating arm 104 has a plurality of movable joints 112which allow for adjustable positioning of the portable X-ray unit 10 inrelation to the patient. A collection of operatories which share aportable X-ray unit 10 may be configured in several different ways. Forexample, each operatory may include its own articulating arm 104 andcontrol circuitry 40, 60, while a single portable X-ray unit 10 andcable 110 is transported from operatory to operatory. The provision ofthe cradle 108 on the end of the articulating arm 104 provides for quickand convenient connection of the portable X-ray unit 10 into theequipment of the operatory. Alternatively, each operatory may beequipped with an articulating arm 104 and the control circuitry 40, 60and portable X-ray generator 10 may be transported from operatory tooperatory as a unit. This would further reduce the equipment costsexperienced by the owner.

If an articulating arm 104 is utilized to hold the portable X-ray unit10 during operation, a remote control firing mechanism may be used inplace of the enable and fire switches 36 and 38 on the unit 10. Suchremote control firing mechanism may be hard wired to the unit 10, or maybe a wireless remote control utilizing infrared or low frequency RFsignals. The use of such a remote control firing mechanism will allowthe operator to leave the room prior to the generation of X-rays by theportable X-ray generator 10. Alternatively, the portable X-ray generator10 may be utilized by the operator without leaving the room due to thegreatly reduced X-ray dose which is generated by the X-ray generator 10.In this situation, the use of the articulating arm 104 will be optional,as the operator may simply hold the X-ray generator 10 in his or herhand during use. A further option is that the cable 110 may beintegrated into the articulating arm 104 and terminate at a connector(not shown) within the cradle 108, such that the portable X-raygenerator 10 may be coupled to the cradle 108 wherein the connector 34of the portable X-ray generator 10 mates with the connector on the endof the cable 110. Such an arrangement will minimize the number of wireswhich are exposed at the dental unit 102.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiment has been shown and described and that allchanges and modifications that come within the spirit of the inventionare desired to be protected.

What is claimed is:
 1. A portable X-ray device, comprising:a handleconfigured to be held by a single hand; an X-ray tube mounted within thehandle; a collimated tube mounted to the handle and positioned such thatX-rays will be emitted into the collimated tube when the X-ray tube isactivated; wiring extending between an interior of the handle and anexterior of the handle and operative to couple an external power supplyto the X-ray tube; an enable switch mounted to the handle; and anexposure switch mounted to the handle; wherein the X-ray tube will onlyemit X-rays when the enable switch and the exposure switch are bothdepressed.
 2. The portable X-ray device of claim 1, furthercomprising:power supply circuitry operative to generate a voltage todrive the X-ray tube; and control circuitry operative to control anexposure time of the X-ray tube; wherein the power supply circuitry andthe control circuitry are not contained within the handle and arecoupled to the handle by the wiring; whereby a weight of the handle issignificantly reduced.
 3. The portable X-ray device of claim 2, whereinthe control circuitry causes a warm-up current to be applied to theX-ray tube when the enable switch is depressed.
 4. The portable X-raydevice of claim 2, wherein the control circuitry causes the power supplycircuitry to generate the drive voltage when the exposure switch isdepressed.
 5. The portable X-ray device of claim 1, further comprising:amulti-pin connector coupled to the handle and conductively coupled tothe wiring.
 6. The portable X-ray device of claim 1, furthercomprising:an image receptor holder coupled to the collimated tube, theholder comprising:a horizontal member having proximal and distal ends; avertical member attached to the horizontal member distal end andextending transversely thereto; and a transverse sliding member mountedto the horizontal member and operative to slide thereon in alongitudinal direction; wherein an X-ray image receptor may be heldbetween the vertical member and the sliding member.
 7. The portableX-ray device of claim 6, wherein the X-ray image receptor is a CCDarray.
 8. The portable X-ray device of claim 1, further comprising:acradle adapted to hold the X-ray device when placed therein, wherein aposition of the cradle with respect to a patient is adjustable.
 9. Aportable X-ray device, comprising:an enclosure; an X-ray tube mountedwithin the enclosure; a collimated tube mounted to the enclosure andpositioned such that X-rays will be emitted into the collimated tubewhen the X-ray tube is activated; wiring extending between an interiorof the enclosure and an exterior of the enclosure and operative tocouple an external power supply to the X-ray tube; power supplycircuitry operative to generate a voltage to drive the X-ray tube,wherein the power supply circuitry is not contained within the enclosureand is coupled to the enclosure by the wiring; whereby a weight of theenclosure is significantly reduced; control circuitry operative tocontrol an exposure time of the X-ray tube, wherein the controlcircuitry is not contained within the enclosure and is coupled to theenclosure by the wiring; a remote control receiver coupled to the powersupply and control circuitry; and a remote control transmitter operablefor wireless transmission of an enable signal and an exposure signal tothe remote control receiver; wherein the control circuitry causes awarm-up current to be applied to the X-ray tube when the enable signalis received by the remote control receiver.
 10. The portable X-raydevice of claim 9, further comprising:a cradle adapted to hold the X-raydevice when placed therein, wherein a position of the cradle withrespect to a patient is adjustable.
 11. The portable X-ray device ofclaim 9, further comprising:an image receptor holder coupled to thecollimated tube, the holder comprising:a horizontal member havingproximal and distal ends; a vertical member attached to the horizontalmember distal end and extending transversely thereto; and a transversesliding member mounted to the horizontal member and operative to slidethereon in a longitudinal direction; wherein an X-ray image receptor maybe held between the vertical member and the sliding member.
 12. Theportable X-ray device of claim 11, wherein the X-ray image receptor is aCCD array.
 13. The portable X-ray device of claim 9, wherein the controlcircuitry causes the power supply circuitry to generate the drivevoltage when the exposure signal is received by the remote controlreceiver.
 14. The portable X-ray device of claim 9, further comprising:amulti-pin connector coupled to the enclosure and conductively coupled tothe wiring.
 15. A method for generating an X-ray image, comprising thesteps of:(a) providing a portable X-ray device, comprising:a handleconfigured to be held by a single hand; an X-ray tube mounted within thehandle; a collimated tube mounted to the handle and positioned such thatX-rays will be emitted into the collimated tube when the X-ray tube isactivated; wiring extending between an interior of the handle and anexterior of the handle and operative to couple an external power supplyto the X-ray tube; an enable switch mounted to the handle; and anexposure switch mounted to the handle; wherein the X-ray tube will onlyemit X-rays when the enable switch and the exposure switch are bothdepressed. (b) grasping the handle with a single hand; (c) depressingthe enable switch with a first finger of the hand; (d) aiming thecollimated tube at an X-ray image receptor, wherein a structure to beimaged is positioned between the collimated tube and the receptor; and(e) depressing the exposure switch with a second finger of the handwhile holding the enable switch in a depressed position.
 16. A methodfor generating an X-ray image, comprising the step of:(a) providing aportable X-ray device, comprising:an enclosure; an X-ray tube mountedwithin the enclosure; a collimated tube mounted to the enclosure andpositioned such that X-rays will be emitted into the collimated tubewhen the X-ray tube is activated; wiring extending between an interiorof the enclosure and an exterior of the enclosure and operative tocouple an external power supply to the X-ray tube; and power supplycircuitry operative to generate a voltage to drive the X-ray tube,wherein the power supply circuitry is not contained within the enclosureand is coupled to the enclosure by the wiring; whereby a weight of theenclosure is significantly reduced; (b) providing an articulating armhaving a cradle thereon, wherein the cradle is adapted to hold the X-raydevice when placed therein; (c) aiming the collimated tube at an X-rayimage receptor, wherein a structure to be imaged is positioned betweenthe collimated tube and the receptor; (d) moving the articulated armsuch that the cradle will hold the X-ray device; (e) depressing anenable switch; and (f) depressing an exposure switch, wherein the X-raydevice will not emit X-rays unless both the enable switch and theexposure switch are depressed.
 17. The method of claim 16, wherein theenable switch and the exposure switch are coupled to the X-ray device bywireless remote control.